This editorial contribution is not only courageous but also an important part of their duties as public-spirited scientists and scholars. Fighting misinformation in the public sphere on complex matters of great importance is a difficult task - and vested interests rely on apathy on the part of those who know, as well as ambivalence on the part of those who don't want to know. It's quite easy, after all, to sow doubt among those whom the status quo favors. That Sheperd, Yager, Mohan and Porter feel a sense of responsibility to speak up says much about our faculty. Their calm reliance on facts and evidence is reassuring, even if what we are doing to the planet is not.
Image: Global map of carbon dioxide concentrations from July 2003, courtesy of Goddard Space Flight Center - Aqua Project Science, via Wikimedia Commons.